lint: Java style (codacy): method DiffImage --> diffImage

Author: jeremydouglass

src/test/e2e/core/E2eTestBase.java

@@ -23,7 +23,7 @@ protected String referenceImage(String path) throws MalformedURLException {
   }
 
   protected float diffImage(File file, String fileURL) throws MalformedURLException, IOException {
-    return ImageUtils.DiffImage(file, new URL(fileURL));
+    return ImageUtils.diffImage(file, new URL(fileURL));
   }
 
   protected float diffImageWithProcessingReference(File file, String referenceURL)

src/test/e2e/util/ImageUtils.java

@@ -14,7 +14,8 @@
  * @author github.com/gaocegege
  */
 public class ImageUtils {
-  public static float DiffImage(File actualFile, URL testURL) throws IOException {
+  
+  public static float diffImage(File actualFile, URL testURL) throws IOException {
     PImage actualImage = new PImage(ImageIO.read(actualFile));
     PImage testImage = new PImage(ImageIO.read(testURL));